Various types of interactively-viewable systems have been attempted over the past couple of decades. Broadcast Videotex systems, such as Teletext systems, utilize a one-way transmission of textual data from a program source to each of a plurality of receivers. Each of the receivers includes a user interface which allows a viewer to select and view desired pages of text included in the transmission. Interactive Videotex systems, such as Viewdata systems, further allow each viewer to transmit one or more signals to the program source. This allows each viewer to select the textual data being transmitted to the receivers.
Interactive cable television systems have been developed which allow each viewer to interact with the program source over a cable television distribution network. Each viewer is capable of providing and/or cable television systems have been utilized to provide services such as video-on-demand and home-shopping.